1. Field of the Invention
The present invention relates to an inspection apparatus used to measure electrical characteristics, etc. of a semiconductor device.
2. Background Art
Japanese Laid-Open Patent Publication No. H03-158764 discloses a probe configured such that the temperature of its tip can be adjusted. This probe is assembled by stacking a plurality of substrates, such as those with a heating element wire or Peltier device mounted thereon.
Japanese Laid-Open Patent Publication No. 2000-138268 discloses a technique for heating a probe substrate with a probe connected thereto using radiant heat from a heating element wire. Thus this technique indirectly heats the probe by heating the probe substrate.
It is known practice to measure electrical characteristics of a semiconductor device in a heated or cooled state. If a probe at room temperature is brought into contact with the semiconductor device in a heated or cooled state, a change in the temperature of the semiconductor device occurs, resulting in reduced inspection accuracy. This temperature change is significant in cases where many probes are brought into contact with the semiconductor device, or the surface of contact between the probe and the semiconductor device is large.
Further, if a high current is caused to flow through the probe when there is a large difference in temperature between the semiconductor device and the probe, the surface of the semiconductor device in contact with the probe is rapidly heated up, so that the surface is subjected to a significant thermal history. It has been found in some cases that this thermal history degrades the characteristics of the semiconductor device.
Therefore, it is preferable to substantially equalize the temperatures of the semiconductor device and the probe. In order to achieve this, the probes disclosed in the above publications are configured such that their temperature can be varied. However, the probe disclosed in the Publication No. H03-158764 is complicated in structure and costly, since it is formed by stacking a plurality of substrates. Further, considerable work is required to replace a probe having a complicated structure.
In the case of the probe disclosed in the above Publication No. 2000-138268, it is difficult to accurately control the temperature of the probe, since the probe is indirectly heated by heating the probe substrate. Further, high power, long duration heating is required to heat up the probe substrate, meaning that heating of the probe substrate is not effective in heating up the probe. Furthermore, the heat resistance of the probe substrate is not high enough to allow the temperature of the substrate to be increased to higher than 150-200° C. As such, it has been found in some cases that the probe cannot be heated to the desired temperature.